The present invention relates generally to the field of magnetic data storage and retrieval systems. More particularly, the present invention relates to a transducing head having a magnetoresistive sensor and first and second dual path conductor/magnet structures arranged in an abutted-junction configuration on opposite sides of the magnetoresistive sensor for stabilizing and for providing current to the magnetoresistive sensor.
A transducing head of a magnetic data storage and retrieval system typically includes a magnetoresistive (MR) reader portion for retrieving magnetic data stored on a magnetic media. The reader is typically formed of several layers which include an MR sensor positioned between two gap layers, which are in turn positioned between two magnetically permeable shield layers. The MR sensor may be any one of a plurality of MR-type sensors, including, but not limited to, anisotropic magnetoresistive (AMR), giant magnetoresistive (GMR), spin valve and spin tunneling sensors.
When the transducing head is placed near a magnetic medium, a resistance of the MR sensor fluctuates in response to a magnetic field emanating from written transitions in the magnetic medium. By providing a sense current through the MR sensor, the resistance of the sensor can be measured and used by external circuitry to decipher the information stored on the magnetic medium. The sense current is provided to the MR sensor via a pair of current contacts.
To operate the MR sensor properly, the sensor must be stabilized against the formation of edge domains because domain wall motion results in electrical noise that makes data recovery impossible. A common way to achieve stabilization is with a permanent magnet abutted junction configuration in which permanent magnet bias elements directly abut opposite sides of the MR sensor. Permanent magnets have a high coercive field (i.e., are hard magnets). The magnetostatic field from the permanent magnets stabilizes the MR sensor, prevents edge domain formation, and provides proper bias.
In recent years, MR sensor widths have decreased to accommodate ever-increasing areal densities of magnetic media. This decrease in MR sensor widths has resulted in increased MR sensor resistivity, which undesirably requires the new design of the external circuitry used to decipher the information stored on the magnetic medium. Thus, there is a need for a MR sensor design that allows for decreased sensor widths without increasing the MR sensor resistivity.